The present invention relates generally to equipment utilized and operations performed in conjunction with subterranean wells and, in embodiments described herein, more particularly provides packer releasing methods.
In general, packers which are releasable by severing a mandrel of the packer using a chemical cutter have no other practical method of releasing the packer. In some cases, such a packer may be releasable by straight shear, that is, by applying an overload to a tubing string attached to the packer. However, this is not practical in many situations, such as that of high performance packers which must withstand extreme tubing loads. Thus, the only practical method of releasing a packer may be chemically cutting through the mandrel.
It would be advantageous to provide other methods of releasing packers which may be used in place of, or in addition to, chemical cutting. Chemical cutting requires specialized crews and equipment, potentially hazardous materials are used (which must be inventoried, stored, handled, transported, disposed of, etc.), and the method is relatively unpredictable in its success. By providing other alternate methods of releasing packers, these alternate methods could be used instead of chemical cutting, or these alternate methods could be used as a backup to the chemical cutting method, or the chemical cutting method could be used as a backup to one or more of the alternate methods.